The role as Naomi Lapaglia, the blonde bombshell trophy wife of stock-market fraudster Jordan Belfort (Leonardo DiCaprio's character), place her firmly on Hollywood's A-list.

She had previously received two Logie Award nominations for her role as Donna Freedman (2008-2011) on the soap opera Neighbours.

Several sources have confirmed Aitken and Robbie are a couple.

The Press understands the pair met on the set of movie Z for Zachariah, which is being filmed in Port Levy.

Aitken's close friend, who did not wish to be named, said Margot Robbie and Aitken had been seeing each other for about one month.

Aitken worked in the film's art department and had become close to Margot Robbie on the film set, he said.

"She's got quite a few roles lined up so she's going to be really busy... but he is in the film industry too so maybe they can find a way to maintain their relationship."

He said despite being a Hollywood star, Margot Robbie seemed like the sort of person who was "not interested in celebrity types".

Aitken's mother Penny said: "We can't and won't comment".

However, pictures of the new couple have appeared on Aitken's Facebook page.

Margot Robbie's mother has also travelled to New Zealand to see her daughter during filming and is believed to have met Aitken.

Margot Robbie, now a brunette, will play Jane in a remake of Tarzan set to be released in 2016.

Aitken's Facebook page says he now lives in Auckland and studied at the New Zealand Film and Television School.

He is the art director for multimedia production company Sakowski Studios, has a profile on modelling and talent agency Ican's website and has also worked on feature movies as well as short films and documentaries.

Z for Zachariah also stars Chris Pine of Star Trek and Chiwetel Ejiofor, who is both a Bafta and Oscar nominee for his leading role in 12 Years a Slave.